SE2051121A1

SE2051121A1 - A prefabricated construction foundation element and a method for building a construction foundation

Info

Publication number: SE2051121A1
Application number: SE2051121A
Authority: SE
Inventors: Erik Goverde
Original assignee: Klara 500/1 Ab
Priority date: 2020-09-25
Filing date: 2020-09-25
Publication date: 2022-03-26
Also published as: WO2022066086A1

Abstract

The invention relates to a prefabricated construction foundation element (100) comprising a top layer (110), an insulation base layer (130), and a reinforcement layer (115) arranged along at least one edge area of the foundation element (100) and between the top layer (110) and the insulation base layer (130). The top layer (110) is a wooden top layer (110) and the reinforcement layer (115) is a wooden reinforcement layer (115). Further, the invention relates to a method for manufacturing a construction foundation (1000) with the prefabricated construction foundation elements (100). The method (500) comprises the step of providing (510) at least two prefabricated foundation elements (100), arranging (520) the foundation elements (100) next to each other on a base layer or support structure, and attaching (530) the foundation elements (100) to each other using an adhesive or a fastening means.

Description

A PREFABRICATED CONSTRUCTION FOUNDATION ELEMENT AND AMETHOD FOR BUILDING A CONSTRUCTION FOUNDATION Technical Field of the Invention The invention relates to a construction foundation element and a method forbuilding a construction foundation using said foundation element. More specif1cally, thepresent invention is related to a prefabricated construction foundation elementcomprising a top layer, an insulation base layer, and a reinforcement layer arrangedalong at least one edge area of the foundation element and between the top layer and theinsulation base layer. Foundation elements of this type are generally used for construction of buildings, such as residential houses, commercial buildings and similar.

Background Construction foundations for buildings are usually made from cement orconcrete, cast in-situ on top of a layer of insulating material. The insulating layerprevents therrnal loss from the ﬂoor inside the finished construction. Depending on soilconditions, it is also common to provide a capillary barrier, usually in the form of alayer of pebbles or gravel beneath the insulation material.

The concrete foundations are generally cast at the building site using mouldsand steel reinforcement bars to support and shape the ﬂuid concrete. When the concretehas set, the construction Work continues.

However, the setting of the concrete can take a long time and the concrete canbe moist for several months depending on the thickness and size of the constructionfoundation, Which in tum causes delay of the construction project. Hence, laying of aﬂoor on the foundation element can be delayed and if a Wooden ﬂoor is arranged on topof the foundation element to soon it can be ruined. Altematively, precautions have to betaken to avoid Water from migrating into a Wooden ﬂoor or other ﬂoor types, Whichmay cause further implications and costs.

Furthermore, concrete and cement are non-environmentally friendly materials, giving rise to pollution and Which are difficult to recycle When needed.

Several attempts have been made to use other materials for buildingfoundations. For instance, US20l8025 l949Al discloses a foundation comprising a firstand second layer of timber poles parallel and spaced apart from each other, and providesa foundation which is light weight, and quick to install. However, insulation materialsand the like still has to be provided, and the timber pole layers have to be aligned andfixed to each other on site.

Hence, there is a need for an improved construction foundation, which mayenable construction work to progress faster and which is believed to be more environmentally sustainable.

Summarv of the Invention According to a first aspect of the invention, the above and other objects of theinvention are achieved, in full or at least in part, by a construction foundation as definedby claim l. According to this claim the above object is achieved by a prefabricatedconstruction foundation element comprising a top layer, an insulation base layer, and areinforcement layer arranged along at least one edge area of the foundation element andbetween the top layer and the insulation base layer. The top layer is a wooden top layerand the reinforcement layer is a wooden reinforcement layer. This prefabricatedfoundation element has several advantages. Firstly, the use of wood for the top layerand the reinforcement layer results in a prefabricated foundation element being lighterthan e. g. a foundation element formed from concrete. The low weight facilitatestransport since vehicles have weight restriction requirements.

Secondly, wood is a sustainable and recyclable material, as opposed to e. g. castconcrete foundations having larger negative impact on the environment. It has beenshown that the carbon footprint of the foundation elements disclosed herein is decreasedcompared to the carbon footprint rendered by a corresponding concrete foundation.

Thirdly, the prefabricated foundation elements results in a fast assemblingprocess and the forrning of a construction foundation does not require any drying periodbefore the construction process may continue. Hence, when a foundation has beenassembled, e.g. by providing a plurality of foundation elements adj acent to each other and, optionally, also opposite each other on a horizontal surface on a building site, a ﬂooring finish can be arranged on top of the Wooden top layer, such as directly on topof the Wooden top layer, Without delay.

The Wooden top layer and the Wooden reinforcement layer may be forrned inengineered Wood or solid Wood. In one embodiment, the Wooden top layer and/or theWooden reinforcement layer is/ are forrned in cross-laminated timber (CLT). The CLT ispreferable since it prevents shear in the Wood, due to that the cross-laminated parts ofthe CLT provides an improved structural rigidity in several directions.

In one embodiment, the Wooden top layer further comprises prefabricatedmachined grooves for receiving cables, pipes, underﬂoor heating and/or plumbing.Further, in a second embodiment, the Wooden top layer is forrned With a hole and amachined inclination area towards the hole for forrning a ﬂoor drain. Theseprefabricated designs are benef1cial since they accelerate and facilitate the constructionprocess. Moreover, the Wooden top layer can be provided With grooves, holes andinclination areas With high precision, e. g. With a precision of l0 mm or less, such as 5mm or 3 mm and e. g. With conventional tools for Wood machining and drilling,compared to When conducted in conventional concrete foundations on site.

In yet another embodiment, the foundation element further comprises aninstallation space embedded in the foundation element. This is advantageous in thatinstallations may be draWn through the prefabricated foundation element, and since itsaves time during the installation process.

In a second aspect, there is provided a method for manufacturing a constructionfoundation With a plurality of prefabricated construction foundation elements asdisclosed herein. The method comprises the steps of providing at least two prefabricatedfoundation elements, arranging the foundation elements next to each other on a baselayer or support structure, and attaching the foundation elements to each other using anadhesive or a fastening means.

This method is advantageous since it is quick and easy, and does not require along period of setting time, as for instance required When forrning a concreteconstruction foundation. Hence, the construction process may proceed immediately after the construction foundation is forrned.

In one embodiment, the method further comprises a step of installinginstallations in an installation space or in prefabricated machined grooves and/or holesof the foundation element. For example, the installations are cables, electric wires,plumbing, ventilation and/or water pipes. This is benef1cial since it accelerates theconstruction process and the installations can be installed with high precision.

Other objectives, features and advantages of the present invention will appearfrom the following detailed disclosure, from the attached claims, as well as from thedrawings. It is noted that the invention relates to all possible combinations of features.

Generally, all terms used in the claims are to be interpreted according to theirordinary meaning in the technical field, unless explicitly defined otherwise herein. Allreferences to “a/an/the [element, device, component, means, step, etc.]” are to beinterpreted openly as referring to at least one instance of said element, device,component, means, step, etc., unless explicitly stated otherwise. The steps of anymethod disclosed herein do not have to be performed in the exact order disclosed,unless explicitly stated.

As used herein, the term “comprising” and variations of this term are not intended to exclude other additives, components, integers or steps.

Brief description of the Drawings By way of example, embodiments of the present invention will now bedescribed with reference to the accompanying drawings, in which: Figure l shows a cross-sectional side view of a prefabricated constructionfoundation element according to one embodiment; Figure 2 shows a cross-sectional side view of a prefabricated constructionfoundation element according to another embodiment; Figure 3 shows a cross-sectional side view of a prefabricated constructionfoundation element according to yet another embodiment; Figure 4 shows a schematic view of a construction foundation comprised froma plurality of prefabricated construction foundation elements showed in Figs l, 2 or 3; Figure 5 shows a cross-sectional side view of a building arranged on top of a construction foundation according to one embodiment; and Figure 6 shoWs a ﬂow chart for a method of building a construction foundation using the prefabricated foundation elements disclo sed herein.

Detailed Description of Preferred Embodiments of the Invention The invention relates to a prefabricated construction foundation element, alsoreferred to as a foundation element herein, and the construction of a constructionfoundation using the foundation elements. With reference to Figs 1-3, a cross-section ofa prefabricated construction foundation element 100 is shown according to differentembodiment examples. The foundation element 100 is arranged for construction offoundations for buildings, including residential houses as Well as commercial buildingsand apartment buildings. For example, foundation element 100 is arranged to bepositioned horizontally or substantially horizontally.

The foundation element 100 comprises a top layer 110, being a Wooden toplayer 110, and a reinforcement layer 115, being a Wooden reinforcement layer 115. Forexample, the Wooden top layer 110 and the reinforcement layer 115 are formed fromsolid Wood or an engineered Wood, such as cross-laminated timber (CLT). For example,the Wooden top layer 110 and the reinforcement layer 115 are formed from CLT madeof spruce Wood. However, any type of Wood may be used to form a CLT. The Woodentop layer 110 is arranged as a board having a top surface and a bottom surfaceconnected through side edges. For example, the Wooden top layer 110 is a continuousboard extending substantially in one plane. For example, the Wooden top layer 110 issubstantially flat and optionally arranged With a substantially uniform thickness. Thereinforcement layer 115 is arranged as a board having a top surface and a bottomsurface connected through side edges. For example, the reinforcement layer 115 is acontinuous board extending substantially in one plane. For example, the reinforcementlayer 115 is substantially ﬂat and optionally arranged With a substantially uniformthickness. The Wooden top layer 110 is arranged on top of the Wooden reinforcementlayer 115, Wherein the Wooden top layer 110 is arranged in parallel With the Woodenreinforcement layer 115. For example, the Wooden top layer 110 is attached to theWooden reinforcement layer 115 by an adhesive and/or fastening means, such as screWs or similar conventional fastening means for fastening boards of Wood to each other.

Further, the wooden top layer 110 has a thickness of between 60 and 250 mm,such as between 60 and 140 mm, such as between 80 mm and 120 mm, preferably, thethickness is about 100 mm. A top layer 110 thicker than 100 mm results in a heavyprefabricated foundation element 100 and a thickness thinner than 60 mm will notprovide suff1ciently satisfying results. The wooden top layer 110 is stiff and rigid, whichis of importance for stability of the foundation element 100 such that it may be coveredwith for instance ﬂoating screed which may be tiled on top without any crack formation.

The use of wood for the top layer 110 and the reinforcing layer 115 provides asustainable foundation element 100 having a lighter weight than e.g. foundationelements made from concrete or cement. The wood also facilitates the prefabricationprocess, since it does not need any setting and drying time, whereby the constructionprocess of the building on top of the wood based foundation element 100 can continueimmediately in various embodiments and at least without substantial delay in otherembodiments. Moreover, the lightness and prefabrication makes the foundationelements 100 easy to handle and the process for forrning a construction foundationusing such foundation elements 100 is a quick and easy process.

In addition, the use of wood is considered to be a more environmentallyfriendly option than using concrete or other non-recyclable materials.

Further, as will be explained more in the following, the wooden top layer 110can be engineered to specific needs of the construction to be built on top since the woodtop layer 110 can be machined/milled to include holes, grooves or inclinations whichgreatly contribute to an easier construction process.

Adj acent to the wooden top layer 110 and the wooden reinforcement layer 115,along at least one side edge of the foundation element 100, the foundation element 100has an edge insulation barrier 120. As shown in Figs 1 and 2, the edge insulation barrier120 is arranged along a vertical side of the foundation element 100, outerrnost from thewooden top layer 110 and the wooden reinforcing layer 115. For example, the edgeinsulation layer barrier 120 protects the foundation element 100 from moisture andcoldness which otherwise could penetrate into the foundation element 100 from the sideedges. The edge insulation barrier 120 extends along a side edge of the wooden top layer 110 and the wooden reinforcement layer 115 and for example along the entire side edge of the foundation element 100. For example, the edge insulation barrier 120 isformed as a plate extending in a plane substantially perpendicular to the wooden toplayer 110. The edge insulation barrier 120 is preferably formed from expandedpolystyrene (EPS), rock wool or other iso lation materials known in the art.

Below the wooden top layer 110 there is a base insulation layer 130. As can beseen in Fig. 1, the base insulation layer 130 supports also the wooden reinforcementlayer 115, wherein a portion of the base insulation layer 130 is arranged below thewooden reiiiforcement layer 115. With reference to Fig. 2 the base insulation layer 130is comprised of a first, a second and a third insulation layer 131, 132, 133. The baseinsulation layer 130 may however comprise fewer or more layers of insulation than thethree layers 131, 132, 133 shown in Figs 2 and 3. For instance, the foundation element100 may comprise a fourth, fifth and sixth insulation layer in addition to the first,second and third insulation layers 131, 132, 133.

The first insulation layer 131 in Fig. 2 is arranged in the same height levelwithin the foundation element 100 as the wooden reinforcement 115, and extends fromthe wooden reinforcement 115 in a direction opposite the edge insulation layer 120. Thesecond and third insulation layer 132, 133 in Fig. 2 extends from the edge insulationbarrier 120. Preferably, the area beneath the reinforcement layer 115 is comprised of ahigh-strength isolation material. The first insulation layer 131, the second insulationlayer 132 and/or the third insulation layer 133 may be formed from expandedpolystyrene (EPS). For example, the first insulation layer 131, the second insulationlayer 132 and/or the third insulation layer 133 are formed as plates extendingsubstantially in parallel with the wooden top layer 110.

Between the first insulation layer 131 and the wooden top layer 110, there is anoptional interrnediate insulation layer 140, comprised of a non-organic perrneableiso lation material. The interrnediate insulation layer 140 enhances the transportation ofhumid air and allows for dehydration of the foundation element 100 in case of leakagesfrom above. A leakage may stem from for instance, a broken sealing layer in abathroom or a water leak in a kitchen and the like. Hence, the interrnediate insulationlayer 140 is preferably applied on those foundation elements 100 arranged below wet rooms such as kitchens, bathroonis, laundry rooms et c.

Another optional feature of the foundation element 100 is a humidity sensor(not shown) which may sense possible water leakages from the construction built ontop.

The prefabricated foundation element 100 shown in Fig. 3 further comprises anedge layer in the form of an outer envelope 150. The outer envelope 150 protects thefoundation element 100 from the environment and prevents moisture from penetratinginto the foundation element 100. The outer envelope 150 covers the edge insulationbarrier 120.

In addition, the prefabricated foundation element 100 comprises an installationspace 160, in which electricity cables, ventilation, pipes and other installations may bedrawn through the foundation element 100. In such case, e.g. cables are installed in theinstallation space 160 and extracted through the wooden top layer 110 at apredeterrnined position adapted for the building to be constructed on top of thefoundation element 100. The installation space 160 may be a ventilated and/or isolatedspace. For example, the installation space 160 is arranged between the wooden top layer110 and the third insulation layer 133. For example, the installation space 160 isarranged between the wooden reinforcement layer 115 and the first insulation layer 130and is optionally embedded in the second insulation layer 132. For example, theinstallation space 160 extends substantially in a horizontal direction through thefoundation element 100, so that cables, pipes and/or similar can extend in a horizontaldirection under the wooden top layer 110 between desired positions and then, if desired,vertically through a hole made in the wooden top layer 110 at the desired location.

An optional diffusion barrier 170 is provided. The diffusion barrier 170 isarranged to protect at least the wooden reinforcement layer 115 and the wooden toplayer 110. For example, the diffusion barrier 170 is arranged between the second andthird insulation layers 132, 133, and between the side edges of the wooden layers 110,115, the second and third insulation layers 132, 133 and the edge insulation barrier 120.The diffusion barrier 170 is indicated with a dashed line in Fig. 3, and is e. g. aconstruction foil. Furthermore, the foundation element 100 in Fig. 3 is provided with aload carrying reinforcement plate 117, which is e.g. formed from a steel sheet. The plate 117 is advantageous when high loads are to be applied on the foundation element 100.

The reinforcement plate 117 supports the wooden reinforcement layer 115 and is e. g.arranged in parallel therewith.

The construction foundation elements 100 are prefabricated and designeddepending on the needs of the building to be built on top. The wooden top layer 110may be machined, eg. by milling, to include grooves/holes for electric wires, waterpipes, sewage, plumbing, ﬂoor heating and the like. The milling may be perforrnedusing a Computer Numerical Control (CNC) tool, which operates from CNC-codedsoftware designed drawings, resulting in very high precision of the cutting/milling anddesign of the prefabricated foundation elements 100.

A CNC-tool may mill with a precision of 3 mm, which is better than theprecision achieved when making such holes, indentions and/or grooves at site in-situ. Inaddition, the CNC-tool may form notches in the top layer 110 to indicate where outerand inner walls 210, 220 (shown in Figs 4 and 5) should be positioned on top of theconstruction foundation 1000. Moreover, the CNC-tool can machine inclinations in thetop layer 110 such that inclinations towards efﬂuent outlets in showers and the like areprefabricated and need not be cast on site.

Further, the prefabricated foundation elements 100 have a vertical axis A,shown in Figures 1-3. The foundation elements 100 may be used as an edge foundationelement, or as a part of a complete construction foundation 1000 (shown in Fig. 4). Insuch case, the foundation element 100 is mirrored about the axis A, such that anopposite end side also comprises a wooden reinforcement 115 and the edge insulationbarrier 120, an outer envelope 150 et. c. The prefabricated foundation elements 100 maybe attached to each other by an adhesive, such as a glue, or they may be fastened to eachother by fastening means, such as bolts or screws, to form a construction foundation1000 (shown in Fig. 4).

The foundation element 100 may be arranged at least partially below groundlevel, such that the top layer 110 is elevated above ground level and the remaining partsof the foundation element 100 are arranged below ground level. The foundationelements 100 and parts thereof presented in the figures are not in scale.

Fig. 4 shows a top view of a construction foundation 1000 comprised of four prefabricated foundation elements 100. A building 200 having walls 210 and inner walls 220 is arranged on top of the construction foundation 1000. Each foundation element100 has a length L and a width W. A typical width L of the element is between 0,5 and6 meters, preferably 2 and 5 meters, and even more preferably 3 meters. The width W iseg. between 1 and 12 meters, such as 2-10 meters or 6-8 meters. However, the width Wmay be larger than 12 meters. These dimensions are advantageous since a standardprivate house is usually built with a width of up to 12 meters and the dimensions arefavourable when considering transportation. Foundation elements 100 of up to 3 x 12meters will fit inside a transportation truck. In the upperrnost foundation element 100 ofFig. 4, grooves 180 have been pre-milled in the wooden top layer 110 (not shown) to fitcables for a ﬂoor heating system.

An electricity line 190 indicated by a dashed line in Fig. 4 has been arranged inthe foundation elements 100 to draw electricity through the construction foundation1000 between inner walls 220. The pre-milled grooves 180 and the design of space forelectric wires 190 are examples of how the prefabricated foundation elements 100 maybe designed specifically for special needs in different buildings.

The foundation elements 100 are preferably mounted on the ground, such as apacked foundation bed which may be covered with an even leveling layer comprised ofe. g. sand. Optionally, the foundation element(s) 100 is arranged on top of a supportstructure comprising a pillar or a plurality of pillars. For example, the foundationelement(s) 100 is arranged on top of a pillar or a plurality of pillars above ground level.When the foundation element 100 is arranged on top of pillars, the outer envelope 150extends to cover also the bottom of the foundation element 100 facing the pillars.

Fig. 5 shows a cross-sectional side view of a house 200 and a constructionfoundation 1000 made of foundation elements 100 according to one embodiment. Theouter walls 210 and the inner wall 220 are arranged on the foundation element 100.Beneath each wall 210, 220, the foundation element 100 comprises a reinforcementlayer 1 15 arranged beneath the wooden top layers 1 10. The foundation element 100 inFig. 4 further comprises edge insulation layers 120, interrnediate insulation layers 140,the base insulation layer 130 and the installation spaces 160. However, the foundationelement 100 as described above or as shown in Figs 1-3 is equally applicable, as explained above. 11 The grooves 180 for ﬂoor heating cables or pipes are machined in the top layer110 as shown in Fig. 5. The electricity 190 is drawn through the foundation element 100through the installation space 160, through the wooden top layer 110 at the desiredposition and further on, e.g. to a final position in a wall 210, 220 through a milledgroove (not illustrated) in the top surface of the wooden top layer 110. In Fig. 5,electricity 190 is drawn through the foundation element 100. However, as describedabove, also water pipes, sewage pipes and ventilation may be arranged in the foundationelement 100 in the same way as the electricity 190 shown in Fig. 5. In the embodimentof Fig. 5 the foundation element 100 is provided with an inclination area 195. Forexample, the inclination area 195 is milled in the wooden top layer 110. For example,the inclination area 195 is connected to a hole arranged through the wooden top layer110, said hole connecting the inclination area 195 with the installation space 160, tofacilitate installation of a floor drain connected to a drain pipe in the installation space1 60.

With reference to Fig. 6, a ﬂow chart for a method 500 for forrning aconstruction foundation 1000 using the prefabricated foundation elements 100 is shown.The method 500 comprises the steps of providing 510 the foundation elements 100 to abuilding site, and arranging 520 at least two prefabricated foundation elements 100 nextto each other on a packed base layer (not shown), and finally attaching 520 thefoundation elements 100 to each other using an adhesive or fastening means. Themethod 500 is easy and enables a fast formation of a sustainable constructionfoundation 1000.

The prefabricated foundation element 100 disclo sed herein facilitates theformation of construction foundations. Firstly, as explained and exemplif1ed above, thedegree of pre-fabrication is high, meaning that details specific to each construction maybe incorporated and prefabricated in the foundation element 100. This results in an easyand quick mounting process of the construction foundation 1000. Since the foundationelement 100 is prefabricated it can be built industrially and enjoy the advantages ofoptimisation and repetitive effects.

The prefabrication also decreases the risk of errors in the construction foundation, and errors in the construction foundation may be difficult, expensive and 12 time consuming to correct. Further, since the prefabrication enables a fast mountingprocess, the construction foundation for a private house may be finished on less than aday, for instance during half a day. Hence, the need for weather protection is decreased.

Thirdly, the foundation elements 100 are based on wood instead of concrete,which have less negative impact on the environment and the climate. It is estimated thatthe wooden prefabricated foundation elements 100 give rise to a significantly loweredcarbon footprint of the carbon footprint rendered by a corresponding concretefoundation.

In addition, the use of wooden materials makes the foundation element 100much lighter than other foundation elements known in the art, and there is no need forthe use of cranes or other vehicles to align and assemble the foundation elements 100.The light weight also enables several foundation elements 100 to be transported at once,since weight otherwise is a limitation during transportation.

Yet another advantage with the foundation elements 100 is that they do notrequire a setting and drying period, as required by concrete foundations. In some cases,the foundation cast of concrete/ cement require up to as much as 3 months before theconstruction project can continue, and ﬂoor and/or waterproofing sheets can be arrangedon top of the concrete foundation. However, once the foundation elements 100 are putinto place, the construction of the building on top of the formed construction foundation1000 may continue almost immediately, since no drying or setting time is required.Even in the event an adhesive is used to attach foundation elements 100 together, thedrying period for the adhesive is much shorter than for the setting and drying time ofconcrete.

Furthermore, the foundation elements 100 withstand large loads (both pointloads and line loads) and may bear large buildings and constructions. For instance, thefoundation elements 100 may withstand the load of a building of four stories when usedin its standard design. Also, the foundation elements 100 are energy efficient, meaningthat they give rise to low heat leakages and help preserve the energy within the building,and that therrnal bridges are kept at a minimum level.

The foundation elements 100 are also inexpensive. An estimated calculation shows that considerable savings of the cost for the construction foundation of a private 13 house may be saved using the foundation elements 100 disclosed herein compared to atraditional concrete cast foundation.

The foundation elements 100 disclosed herein are rectangular. However, thefoundation element 100 may have any other suitable geometrical shape, such as a squareor triangular shape. Furthermore, a private house often comprise bay Windows,entrances extending from or being WithdraWn from the base of the building, or roundedarced shapes. In fact, a building may have various geometrical shapes. Therefore, theedge features of the foundation element 100 being the Wooden reinforcement 115, theedge insulation layer 120 and the building envelope 150 may extend partially or entirelyalong the circumference of the foundation element 100, independent of the shape of thefoundation element 100.

Optionally, the edge features being the Wooden reinforcement 115, the edgeinsulation layer 120 and the building envelope 150 partially extends around thecircumference of the foundation element 100. For instance, if the foundation element100 is rectangular shaped, the edge features extend along one, two or three of the foursides of the foundation element 100. For instance, if the foundation element is semi-circular, the edge features may extend only along the rounded periphery of thefoundation element 100. Further, a single foundation element 100 may be used to forma construction foundation 1000. In such case, the reinforcement layer 115, thereinforcement plate 117, the edge insulation layer 120, and/or the outer envelope 150extends around the entire circumference of the foundation element 100.

In the claims, the term “comprises/comprising” does not exclude the presenceof other elements or steps. Furthermore, although individually listed, a plurality ofmeans, elements or method steps may be implemented by e.g. a single unit or processor.Additionally, although individual features may be included in different claims, thesemay possibly advantageously be combined, and the inclusion in different claims doesnot imply that a combination of features is not feasible and/or advantageous. Inaddition, singular references do not exclude a plurality. The terms “a”, “an”, “f1rst”,“second” etc. do not preclude a plurality. Reference signs in the claims are providedmerely as a clarifying example and shall not be construed as limiting the scope of the claims in any Way.

Claims

1. A prefabricated construction foundation element (100) comprising a toplayer (110), an insulation base layer (130), and a reinforcement layer (115) arrangedalong at least one edge area of the foundation element (100) and between the top layer(110) and the insulation base layer (130), c h a r a c t e r i s e din that the top layer(110) is a Wooden top layer (110) and the reinforcement layer (115) is a Wooden reinforcement layer (1 15).

2. The foundation element according to claim 1, Wherein the Wooden toplayer (110) and the Wooden reinforcement layer (115) are formed in engineered Wood or solid Wood.

3. The foundation element according to claim 2, Wherein the Wooden toplayer (110) and/or the Wooden reinforcement layer (115) is/ are formed in cross- laminated timber (CLT).

4. The foundation element according to any of claims 2-3, Wherein theWooden top layer (110) is formed as a single continuous board, Wherein the Woodenreinforcement layer (115) is formed as a single continuous board, and Wherein the Wooden top layer (110) is attached on top of the Wooden reinforcement layer (115).

5. The foundation element according to any of the preceding claims,Wherein the Wooden top layer (110) further comprises prefabricated machined grooves for receiving cables, pipes, underﬂoor heating and/or plumbing.

6. The foundation element according to any of the preceding claims,Wherein the Wooden top layer (110) is formed With a hole and a machined inclination area towards the hole for forming a ﬂoor drain.

7. The foundation element according to any of the preceding claims, furthercomprising an edge insulation barrier (120) arranged along at least one side edge of thefoundation element (100), and an outer envelope (150) arranged as an outer edge surface of at least one side edge of the foundation element (100).

8. The foundation element according to any of the preceding claims, furthercomprising a diffusion barrier (170) extending between the edge insulation barrier (120)and the top layer (110), between the edge insulation barrier (120) and the reinforcementlayer (115) and under the top layer (110) and under the reinforcement layer (115).

9. The foundation element according to any of the preceding claims, whereinthe insulation base layer (130) is comprised of a plurality of insulation layers, preferablya first insulation layer (131), a second insulation layer (132) and a third insulation layer (133).

10. The foundation element according to any one of the preceding claims,further comprising an interrnediate insulation layer (140) arranged between the top layer (110) and the insulation base layer (130).

11. The foundation element according to any of the preceding claims, further comprising an installation space (160) embedded in the foundation element (100).

12. The foundation element according to any of the preceding claims,wherein the foundation element (100) further comprises a reinforcement plate (117),preferably formed from a steel sheet and arranged between the reinforcement layer (115) and the insulation base layer (130).

13. The foundation element according to any of the preceding claims,wherein the insulation base layer (130) if formed from expanded polystyrene (EPS), andwherein the interrnediate insulation layer (140) is formed from a non-organic perrneable insulation material. 16

14. The foundation element according to any of the preceding claims, Wherein the diffusion barrier (170) is made of a construction foil.

15. A method for manufacturing a construction foundation (1000) Withprefabricated construction foundation elements (100) according to any of claims 1 to 14,said method (500) comprising the steps of: - providing (510) at least tWo prefabricated foundation elements (100); - arranging (520) the foundation elements (100) next to each other on abase layer or a support structure; and - attaching (530) the foundation elements (100) to each other using an adhesiVe or a fastening means.

16. The method according to claim 15, further comprising a step of installing(540) installations in an installation space (160) or in prefabricated machined groovesand/or holes (180) of the foundation element (100), said installations preferably being cables, plumbing, Ventilation and/or Water pipes.